Structured output

A decision answers questions: result, confidence and the action. A structured output destination (json) also hands back an object ready for your system — the ticket to open, the order to update, the lead to create — and checks it against the fields you define before it leaves Dcision.

It comes back in the response's top-level output:

{
  "result": { "route": "support", "priority": "high" },
  "action": "continue",
  "output": { "awb": "1Z999AA10123456784", "team": "support", "priority": 3, "summary": "Package is 3 days late" },
  "destinations": [
    { "key": "ticket", "type": "json", "mode": "template", "status": "completed", "output": { "awb": "1Z999AA10123456784", "team": "support", "priority": 3, "summary": "Package is 3 days late" } }
  ]
}

Two ways to fill itCopy Anchor Link

Use template when the values already exist — in the state or in the answers. Use extract when they are buried in text: an order number in an e-mail, a name in a chat message.

The fieldsCopy Anchor Link

The schema is a JSON Schema object, the same format LLM providers use for structured outputs:

{
  "type": "object",
  "properties": {
    "awb": { "type": "string", "description": "The tracking number" },
    "team": { "type": "string", "enum": ["sales", "support", "billing"] },
    "priority": { "type": "integer", "minimum": 1, "maximum": 4 },
    "items": { "type": "array", "items": { "type": "string" }, "maxItems": 10 },
    "note": { "type": ["string", "null"] }
  },
  "required": ["awb", "team"]
}

Fields that aren't in the schema are not accepted. Limits: up to 3 levels of nested objects, 50 fields in total and 8 KB of schema; the output itself is up to 16 KB. In the editor, Output fields builds the schema row by row; the JSON Schema tab shows it as JSON, and you can paste one there.

Template modeCopy Anchor Link

The template is JSON with variables, encoded like the body of an API request: outside quotes a variable becomes a JSON value, inside quotes it becomes text.

{
  "key": "ticket",
  "type": "json",
  "when": { "conditions": [{ "field": "route", "on": "output", "operator": "eq", "value": "support" }] },
  "params": { "awb": { "from": "state.awb", "required": true } },
  "json": {
    "mode": "template",
    "schema": { "type": "object", "properties": { "awb": { "type": "string" }, "team": { "type": "string" }, "priority": { "type": "number" }, "summary": { "type": "string" } }, "required": ["awb", "team"] },
    "template": "{\"awb\": {{params.awb}}, \"team\": {{result.route}}, \"priority\": {{scores.priority}}, \"summary\": \"Customer said: {{state.message}}\"}"
  }
}

• Text from the state can't break the JSON: quotes and line breaks are escaped wherever the variable is.
• Secrets can't be used — the output goes back to the caller. {{secrets.NAME}} is refused when you save.
• When you save, the template must be valid JSON with sample values and have the required fields. Fill from fields in the editor writes a starting template: a field named like a state field, a question, a composite or a param reads it.

Extract modeCopy Anchor Link

"json": {
  "mode": "extract",
  "schema": { "type": "object", "properties": { "order_id": { "type": "string" }, "customer": { "type": "string" }, "request": { "type": "string", "enum": ["refund", "exchange", "tracking"] } }, "required": ["order_id", "request"] },
  "provider": "openrouter",
  "model": "openai/gpt-5-mini",
  "instructions": "Extract the order this customer is writing about.",
  "input": "{{state.message}}",
  "temperature": 0,
  "maxTokens": 1024,
  "timeoutMs": 20000
}

Dcision sends the schema in the provider's strict structured-output mode (response_format: json_schema). Strict mode needs every field, so optional fields go as nullable and the nulls the model writes for them are removed before validation. If the answer still doesn't fit — invalid JSON, a value outside enum, a missing field — Dcision sends it back once with the problems, within the same timeoutMs.

When it failsCopy Anchor Link

A structured output never fails the decision. The entry comes back with "status": "failed", an error and, when the object didn't match, the issues:

{
  "key": "ticket",
  "type": "json",
  "mode": "template",
  "status": "failed",
  "error": "The output doesn't match the schema.",
  "issues": [{ "path": "/awb", "message": "Must not be null." }]
}

issues[].path is a JSON Pointer to the value (/items/2). The top-level output is:

In the Playground and the logsCopy Anchor Link

• In the Playground, template destinations always run (they're free); extract destinations show the prompt and the strict schema that would be sent ("status": "preview") unless you run destinations for real.
• The execution log keeps the output when the decision stores outputs (storeOutput); with storeOutput: false it keeps only whether the output was built.
• The SDKs expose it as decision.output — in TypeScript, typed with dcision.decide<Result, Output>(…).